How Sweden cut traffic congestion

By Brad Plumer – Traffic congestion sometimes seems like an utterly in­trac­table problem. If a city suffering from gridlock tries to construct new roads to ease the pressure, traffic usually just increases to fill the extra space. Same thing when new bus and subway lines get built. Yet a few cities like Stockholm, London, and Singapore have taken a more market-orientedapproach to congestion.

Stockholm puts a flat $2.60 charge on all vehicles entering the city during peak hours and a $1.30 to $2 levy at other times throughout the day. And, so far, traffic appears to have stayed at reduced levels since the system came into effect in 2007.